In the reference patent, there is described and claimed a system for sorting and processing articles of varying descriptions and physical sizes and weights. More particularly, the system finds application in sorting machinable mail flats. Three major components are utilized, namely, a mini-carrier to support each item to be processed, a monorail conveyor to transport the carriers, and magnetic coding on the carriers to provide control data.
In operation, the mail flats arrive at an induction station, where each flat is clipped to a waiting mini-carrier. The flat is then advanced to a viewing station where an operator keys the desired code, based, for example, on the ZIP code destination of the flat. At an encoding station further downstream, a destination code determined by the operator-keyed data is encoded on the carrier's magnetic stripe. The flat then enters the conveyor distribution system in which code readers read the escort memory data on the carrier's stripe and direct the flat via appropriate gating to a storage destination or output accumulation rack to await a secondary sort or alternately, an output when the rack if full or a sweep is otherwise desired. Such a system finds particular application in large installations where space allocation for the required large numbers of storage destinations presents no problem. Small and medium Post Offices, for example, may not be able to avail themselves of the system due to space limitations.
In considering solutions to the space problem, it was noted that during actual operation, the storage destinations (output accumulation racks) of the referenced patented system were seldom filled to capacity and more often remained approximately half full. Therefore, 50% of the storage space in the racks remained unused. Moreover, the many relatively small storage destinations did not offer the economy of storage space utilization which might be achieved in a few larger storage mediums.
The recirculation buffer subsystem of the present invention provides an efficient and cost effective solution to the aforementioned space problem.